diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S')
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S b/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S index 35eb09cd0c..54a47e111f 100644 --- a/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S +++ b/nptl/sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S @@ -31,6 +31,127 @@ .align 16 __pthread_rwlock_rdlock: cfi_startproc + movq $NRW_RC, %rax + LOCK + xaddq %rax, NRW_WORD(%rdi) + js .Lundo + +.Lagain1: + movq $(NRW_WL|NRW_WP), %rcx + movq $(NRW_WL|NRW_WW_MASK), %rdx + testq %rax, %rcx + setnz %cl + testq %rax, %rdx + setnz %dl + orb %cl, %dl + jnz .Lwait + + xorl %eax, %eax + ret + +.Lwait: movq $NRW_WL, %rcx + testq %rcx, %rax + jz 4f + + movl %fs:TID, %ecx + cmpl %ecx, WRITER(%rdi) + je .Ldeadlk + +4: xorq %r8, %r8 + movq $NRW_RC, %rdx + addq %rdx, %rax + movq $(NRW_WL|NRW_AR), %rcx + movq $(NRW_WP|NRW_WW_MASK), %rdx + testq %rax, %rcx + setz %cl + testq %rax, %rdx + setnz %dl + testb %dl, %cl + jz 1f + + movq $NRW_RW-NRW_RC, %rdx + addq %rax, %rdx + LOCK + cmpxchgq %rdx, NRW_WORD(%rdi) + jnz .Lagain1 + + movq $NRW_RC_MASK, %rax + testq %rdx, %rax + movl $1, %r8d + jz .Lwake_waiter + +1: xorq %r10, %r10 + movl $NRW_R_WAKEUP, %r9d + movl $(FUTEX_WAIT_BITSET|FUTEX_PRIVATE_FLAG), %esi + xorl PSHARED(%rdi), %esi + leaq NRW_WORD+4(%rdi), %rdi +2: shldq $32, %rax, %rdx + movl $__NR_futex, %eax + syscall + movq -4(%rdi), %rax + +5: movq $(NRW_WL|NRW_WP), %rcx + movq $(NRW_WL|NRW_WW_MASK), %rdx + testq %rax, %rcx + setnz %cl + testq %rax, %rdx + setnz %dl + orb %cl, %dl + jnz 2b + + testl %r8d, %r8d + jz 3f + + movq $NRW_RC-NRW_RW, %rcx + addq %rcx, %rdx + LOCK + cmpxchgq %rdx, -4(%rdi) + jnz 5b + +3: xorl %eax, %eax + ret + +.Lwake_waiter: + movq %rdx, %r10 + movl $__NR_futex, %eax + movl $(FUTEX_WAKE_BITSET|FUTEX_PRIVATE_FLAG), %esi + xorl PSHARED(%rdi), %esi + leaq NRW_WORD(%rdi), %rdi + movl $1, %edx + movl $NRW_W_WAKEUP, %r9d + syscall + leaq -NRW_WORD(%rdi), %rdi + movq %r10, %rdx + jmp 1b + +.Lundo: movq $-NRW_RC, %rcx + movq %rax, %rdx + subq %rcx, %rax + LOCK + cmpxchgq %rdx, NRW_WORD(%rdi) + jz .Lret + + movq $NRW_RC_OVFL, %r8 +.Lagain2: + testq %r8, %rax + jz .Lagain1 + leaq (%rax,%rcx), %rdx + LOCK + cmpxchgq %rdx, NRW_WORD(%rdi) + jnz .Lagain2 + +.Lret: movl $EAGAIN, %eax + ret + +.Ldeadlk: + movq $NRW_RC, %rdx + LOCK + subq %rdx, NRW_WORD(%rdi) + + movl $EDEADLK, %eax + ret + +#if 0 xorq %r10, %r10 /* Get the lock. */ @@ -168,6 +289,7 @@ __pthread_rwlock_rdlock: subq $MUTEX, %rdi #endif jmp 13b +#endif cfi_endproc .size __pthread_rwlock_rdlock,.-__pthread_rwlock_rdlock |